The objective of this program is to provide a productive learning experience in medical research related to diseases of the gastrointestinal tract and liver. The individuals who are accepted into this program will, for the most part, have an M.D. or M.D./Ph.D degree and will have completed their training in internal medicine, surgery or pediatrics. A few individuals with a Ph.D. may also be accepted into the program. Another unique objective of this program is to assist in training academic individuals who are interested in the special diseases of Mexican Americans. The rationale for the program is to provide the opportunity for an in depth research experience under an outstanding mentor that will allow each trainee to learn a variety of research techniques and, in the end, to compete successfully for a position in academic medicine and for research funding. This program is flexible, but basically has two components. The first is designed for the individual interested in basic research and involves learning a variety of techniques in biochemistry, physiology and molecular biology that will be required for a successful basic science career. The second is designed for individuals interested in patient related, clinical research. This latter program has formal instructions in study design, statistics, ethical considerations and other information related to human research. Such individuals will also undergo mentoring by major clinical investigators in this university. In addition to this research training, all trainees, except those with a Ph.D., will undergo clinical training in the areas of hepatology and gastroenterology. Overall, it is anticipated that the period of training will last from four to six years for the four individuals for whom support is requested. There are a large number of possible mentors in this training program so that individuals may be prepared for full-time careers in teaching and research in a variety of areas. These areas include studies related to the understanding and treatment of a variety of liver diseases, the elucidation and prevention of such common disorders as acute fatty infiltration of the liver and gallstones, the understanding and treatment of important illnesses such as inflammatory bowel disease and the reasons for malignant transformation of cells in various areas of the gastrointestinal tract. The program is designed, therefore, to train individuals who will be effective teachers of gastroenterology as well as successful investigators of important illnesses affecting the gastrointestinal tract and liver.